Thousands more visitors gained entry to the popular Smithsonian museum on four Wednesdays last month, pushing officials to extend the program into May. April’s Walk-Up Wednesday crowds were larger than its Saturday crowds, typically the museum’s busiest day, according to Smithsonian spokeswoman Linda St. Thomas.

“Clearly it was successful,” St. Thomas said. “It allowed more visitors to enjoy the museum.”

There were 9,500 visitors on April 4, the middle of the busy Easter week, and about 8,900 the second Wednesday, April 11, St. Thomas said. The last two Wednesdays attracted 8,000 and 7,800 visitors, respectively. Those numbers exceeded visitor tallies on all four Saturdays in April, which averaged 6,825.

Visitor numbers also eclipsed Tuesday totals last month, which ranged from 4,500 and 7,000, St. Thomas said.

Since its opening Sept. 24, 2016, the newest Smithsonian museum has welcomed more than 3.5 million visitors. It has used timed passes to control crowd size and reduce lines. St. Thomas said officials were not yet considering eliminating all passes.

The museum has distributed thousands of free passes on the first Wednesday of each month — on May 2 it will distribute passes for August — but many are not used. About 3,000 visitors on each Wednesday in April had advance passes and were given priority entry, according to St. Thomas. No visitors were turned away.

In addition to advance passes, the museum distributes same-day passes online daily at 6:30 a.m. Walk-up admission is available after 1 p.m. weekdays, if capacity allows.

Peggy McGlonePeggy McGlone is a reporter for The Washington Post, covering arts in the Washington region. Before coming to The Post, she worked for the Star-Ledger in New Jersey as a features writer and beat reporter covering arts and education. Follow